Nevertheless, several genes underlying ASDII have been identified, including transcription (co-)factor encoding genes such as GATA4, NKX2.5, and TBX5, and sarcomeric protein encoding genes such as ACTC1, MYH6 and MYH7. Secundum ASDs associated with atrioventricular block are linked to NKX2.5 mutations [6, 7]. Here, NKX2-5 is linked to atrioventricular block.